JP3040306B2 - Steam cleaning equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam cleaning apparatus for cleaning the surface of an object to be cleaned with steam.

[0002]

2. Description of the Related Art Conventionally, various impurities have adhered to the surface of a semiconductor substrate such as a silicon wafer and a mask in a processing step, and a cleaning method for removing these impurities includes a steam cleaning method (for example, Japanese Unexamined Patent Publication No. Hei.
-41139 gazette). In such a vapor cleaning method, for example, isopropyl alcohol (IPA) is used as the cleaning liquid, and a collecting pan for collecting dewdrops of vaporized gas on the surface of the semiconductor substrate is provided directly below the substrate.
Therefore, the condensed liquid dropped containing the impurities accumulates in the collecting pan and is discharged through the discharge pipe connected to the collecting pan, but the liquid once accumulated in the collecting pan is heated again by the steam heat from below. There is a possibility that the impurities may be re-evaporated while containing the impurities and the impurities may adhere to the substrate again.

[0003] Japanese Patent Application Laid-Open No. 2-185031 discloses a steam drying apparatus, in which steam generated once is blown by a steam nozzle. In a hot tub. Therefore, there is a possibility that the condensed water which contains the impurities and is dropped may re-evaporate in the hot tub and the impurities may adhere to the substrate again.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, a main object of the present invention is to provide a steam cleaning apparatus capable of preventing a liquid dropped from a body to be cleaned onto a recovery pan from re-evaporating. Is to provide.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided a cleaning liquid evaporating chamber for generating vapor of a cleaning liquid for vapor cleaning a body to be cleaned held in an upper space of a casing. A cleaning pan provided between the substrate and the cleaning liquid evaporation chamber for recovering the cleaning liquid dropped from the cleaning target, wherein the recovery pan has a central part facing upward. A projection is formed at the top of the projection, and at the top of the projection, an opening for passing steam from the cleaning liquid evaporation chamber to the substrate accommodating chamber is provided, and a roof that covers an upper portion of the opening and has an upward projection is provided. This is achieved by providing a steam cleaning device characterized by being provided. In particular, a discharge hole for discharging the dripping liquid recovered by the recovery pan to the outside of the casing is provided in a peripheral wall portion of the substrate storage chamber of the casing and directly above a peripheral edge of the recovery pan. It is good to be.

[0006]

In this way, the liquid containing the impurities dropped on the collecting pan flows down toward the peripheral portion of the collecting pan formed in an umbrella shape, so that the liquid around the opening through which the steam from the steam generating chamber passes is formed. Since it does not remain in a portion directly below a certain substrate, it does not re-evaporate. Further, the liquid that has flowed down toward the peripheral portion of the collecting pan can be quickly discharged through a discharge hole provided in the peripheral wall portion of the casing and directly above the peripheral portion of the collecting pan.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a preferred embodiment of the present invention.

FIG. 1 is a schematic longitudinal sectional view showing a steam cleaning apparatus to which the present invention is applied. In the present apparatus, as shown in the figure, a semiconductor substrate 2 as an object to be cleaned is held in an upper space of a container-like casing 1 whose entire surface is covered, and a cleaning liquid S is stored at the bottom of the casing 1. The cleaning liquid S is heated to a predetermined temperature by a heating means such as a heater or hot water (not shown) and turns into a vapor, thereby cleaning the surface of the semiconductor substrate 2 with the vapor. A collecting pan 3 is provided at an intermediate portion in the vertical direction of the casing 1 for collecting a dropping liquid that is condensed and drops on the surface of the semiconductor substrate 2. ,
A recovery pan 3 is provided at an intermediate portion so as to be divided into an upper substrate accommodating chamber 4 and a lower cleaning liquid evaporation chamber 5.

The upper surface of the casing 1, which is the top of the substrate accommodating chamber 4, can be opened and closed. The semiconductor substrate 2 conveyed from the previous process can be moved from the upper surface of the casing 1 to the substrate accommodating chamber 4 while being supported by the carrier 6. It can be stored inside. A cleaning liquid is stored in the bottom of the cleaning liquid evaporation chamber 5, and is heated to a predetermined temperature by a heating means such as a heater or hot water (not shown). In addition, the cleaning liquid is not limited to the organic solvent and pure water, but may be selected according to a cleaning target.
It is preferable to use a liquid containing an acid, a salt, a base, or a combination thereof, and further, hydrogen peroxide.

The recovery pan 3 is formed by projecting a plate material with its central portion including immediately below the substrate 2 facing upward, and the peripheral edge thereof is connected to the inner peripheral surface of the casing 1. An opening 7 through which the vapor of the cleaning liquid evaporated from the cleaning liquid evaporation chamber 5 passes through the substrate storage chamber 4 is provided at the protruding top of the recovery pan 3. Therefore, both chambers 4 and 5 are separated by the collecting pan 3 except for the opening 7.

Above the collecting pan 3, a roof 8 having a somewhat larger cross-sectional area than the opening 7 and projecting upward is provided on the upper surface of the collecting pan 3 so as to cover the upper part of the opening 7. The supporting member 9 is supported by an upright column 9 provided on the outer peripheral portion of the supporting member 7. Therefore, a gap is provided between the upper surface of the recovery pan 3 and the roof 8 to allow the steam rising from the opening 7 to escape from the side. The collecting pan 3 and the roof 8 are surface-treated with a hydrophobic material, for example, a fluororesin material.

A cooler 10 is provided on the outer peripheral surface of the casing 1 and around the widened lower half of the substrate accommodating chamber 4. A discharge hole 11 is provided at an appropriate position on the peripheral wall portion of the substrate accommodating chamber 4 of the casing 1 and immediately above a connection portion with the peripheral edge of the collection pan 3, and a discharge pipe 12 is connected to the discharge hole 11. Have been.

In the steam cleaning apparatus constructed as described above, the cleaning liquid stored in the cleaning liquid evaporation chamber 5 is heated to become steam, and the steam is collected by the recovery pan 3 as shown by a broken arrow in FIG. Through the opening 7, escapes from between the collection pan 3 and the roof 8, enters the substrate storage chamber 4, and rises.
Dew forms on the surface of the substrate 2. At this time, impurities on the surface of the substrate 2 are removed, and the dew condensation liquid is dropped. The dripping liquid falls on the upper surface of the roof portion 8 as shown by the solid arrow in the figure, but flows down the roof portion 8 because the roof portion 8 is formed so as to project upward. It falls on the upper surface of the collection pan 3.

Since the collecting pan 3 also has a protruding shape as described above, the dropping liquid dropped on the upper surface thereof moves toward the lower periphery as shown by the solid line arrow, and the liquid falls within the casing 1. It is collected at the connection between the peripheral surface and the peripheral edge of the collection pan 3. The dripping liquid collected on the periphery of the recovery pan 3 as described above is discharged to the outside from the discharge hole 11 through the discharge pipe 12.

As described above, since the dripping liquid does not stay in the vicinity of the opening 7 of the collecting pan 3 which is easily heated by the steam below, the dripping liquid dropped on the collecting pan 5 can be prevented from re-evaporating. In particular, by making the surfaces of the collecting pan 3 and the roof 8 hydrophobic, as described above, the dripping liquid can flow down more quickly toward the peripheral edge of the collecting pan 3. Furthermore, since the dripping liquid collected on the peripheral portion of the collecting pan 3 is cooled by the cooler 10 provided on the outer periphery of the casing 1, it is more reliably prevented from being heated by the lower steam and re-evaporated. Is done.

By forming the casing 1 into a structure that can be divided vertically with the collecting pan 3 as a boundary, the collecting pan 3 can be easily replaced. By doing so, maintenance of the collection pan 3 can be easily performed.

[0017]

As described above, according to the present invention, by providing the collecting pan having the central portion formed in a projecting shape at the top, the liquid condensed and dropped on the substrate by the steam cleaning is removed from the peripheral portion of the collecting pan. The dripping liquid does not stay in the center of the collecting pan which is relatively easily heated by steam, and the re-evaporation of the dripping liquid containing impurities can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a steam cleaning apparatus to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Semiconductor substrate 3 Recovery pan 4 Substrate storage room 5 Cleaning liquid evaporation chamber 6 Carrier 7 Opening 8 Roof part 9 Support post 10 Cooler 11 Discharge hole 12 Discharge pipe

──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Kenichi Uemura 3434 Shimada, Hikari-shi, Nippon Steel Corporation Inside the Hikari Works (72) Inventor Yoshihiro Mori 3434, Shimada, Daiji, Hikari-shi Nippon Steel Corporation Hikari (56) References JP-A-4-280632 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/304 B08B 3/00-3/14

Claims (2)

(57) [Claims] A cleaning liquid evaporating chamber for generating vapor of a cleaning liquid for vapor-cleaning an object to be cleaned held in an upper space of a casing, provided at a lower portion of the casing, between the substrate and the cleaning liquid evaporating chamber. A steam cleaning apparatus provided with a collection pan for collecting a cleaning liquid dropped from the object to be cleaned, wherein the collection pan is formed in a protruding shape with a central portion facing upward,
In addition, an opening for passing steam from the cleaning liquid evaporation chamber to the substrate accommodating chamber is provided at the protruding top portion, and a roof portion that covers above the opening and has a protruding shape is provided. Steam cleaning equipment. 2. A discharge hole for discharging the dripping liquid collected by the recovery pan to the outside of the casing is provided in a peripheral wall portion of the casing and immediately above a peripheral edge of the recovery pan. The steam cleaning apparatus according to claim 1, wherein